Liquid conductor heater



J. R. CONLIN ET AL 2,837,625

LIQUID CONDUCTOR HEATER Original Filed July 30. 1954 2 Sheets-Sheet 1 June 3, 1958 INVENTORS.

M, 10/, ml/w III June 3, 1958 J. R CONLIN ET AL 2,

LIQUID CONDUCTOR HEATER Original Filed Jul so, 1954 2 Sheets-Sheet 2 United States Patent LIQUID CONDUCTOR HEATER James R. Conlin and William Schulz, Reedsburg, Wis., assignors to Hanlrscraft Company, Reedshurg, Wis, a corporation of Wisconsin Original application July 30, 1954, Serial No. 446,912. and this application August 9, 1956, Serial No.

2 Claims. (Cl. 219--40) This invention relates to improvements in liquid conductor heaters of the type which is adapted for use as a sterilizer, vaporizer, bottle warmer, egg cooker or the like. The present application is a division of our co-pending application Serial No. 446,912, filed July 30, 1954.

In a liquid conductor heater of the type referred to a pair of spaced electrodes are commonly mounted on the bottom portion of a vessel adapted to contain a quantity of water or other liquid to be heated and vaporized by the passage of an electric current therethrough between the electrodes. The operation of such a device frequently results in deposits from the water on the electrodes so that their surfaces become coated and their conductivity is impaired. It is, therefore, necessary in some localities to clean the electrodes at in tervals and they sometimes require replacement, so that ready access to the electrodes and the convenient rev moval thereof become important.

It is, therefore, the principal object of the present invention to provide a liquid conductor heater having an electrode assembly which is readily accessible and easily removable from the vessel in which it is mounted. Another object is to provide a liquid conductor heater, such as a sterilizer, in which the heating device is formed as a removable unit mounted in the wall of a vessel containing the liquid and comprising an insulating member on which are mounted spaced electrodes to be connected by the liquid, thereby facilitating the cleaning and repair of the electrodes while at the same time permitting the body of the vessel to be formed of a material cheaper than that required for the insulating member. Other objects of the invention relate to various features of construction and arrangement which will appear more fully hereinafter.

The nature of the invention will be understood from the following specification taken with the accompanying drawings in which one embodiment is illustrated. In the drawings,

Figure 1 is a perspective view of a bottle sterilizer embodying the features of the present invention;

Fig. 2 shows a side elevation of the heating unit embodied in the construction illustrated in Fig. 1;

Fig. 3 shows a partial enlarged horizontal section through the liquid containing vessel of the sterilizer illustrated in Fig. 1, showing a top plan view of the heating unit shown in Fig. 1; and

Fig. 4 shows a vertical section taken on the line 4-4 of Fig. 3.

As illustrated in the drawings, the invention comprises a water containing vessel or base which is formed preferably of plastic material and which is slightly bowed outwardly between its top and lower edges with a horizontal row of vertical ribs 10a extending about the lower edge thereof for ornamental purposes. On opposite sides, the vessel 10 is provided with integral projecting handles 10b by which the entire sterilizer may be convenientlymoved about. The vessel 10 is provided on its inner side with a series of integral projections 10c terminating at their top ends in horizontal shoulders lilo. which are adapted to be engaged by the lower edge of the metal shell or cover 11 adapted to form the chamber in which the major portion of the sterilizing operation takes place. This cover or shell comprises an annular wall 11a which bulges slightly in an outward direction and which is united at its top edge with a fiat top wall 1112 having formed therein a depression in which there is secured a handle 11a. The top wall 116 is further provided with an aperture 11e through which the steam or vapor escapes.

The vessel 10 has a bottom Wall 102 sloping toward its center where it is provided with a tubular downwardly extending projection ill closed at its lower end by a metal plate 12, secured thereto by screws 13. In this central portion of the bottom wall of the vessel 10 there is mounted the heating unit 15 which comprises spaced electrodes 16 and 17 carried by an insulating member 18 formed preferably of porcelain or the like. The insulating member 18 is mounted in the tubular extension 10 which carries an annular inwardly extending flange 10g on which the outer annular portion 18a of the insulating member rests, being attached thereto by a tongue and groove connection 19 and also by a rubber gasket inserted between the contacting surfaces and around the outer margin of the member 18. The electrode 16 rests directly upon the bottom wall of a cavity 182 which is formed in the member 18 and has secured thereto two terminal posts 20 which extend downwardly into the chamber formed by the depending flange 1815 on the member 18. The terminal posts 24} are connected to one terminal of an electric circuit by means of an electric conductor 22.

The central portion of the insulating member 18 has an upwardly extending cylindrical projection 18:! which projects through a central aperture in the lower electrode 16 and forms a support for the upper electrode 17 which is also supported by cone-shaped projections 180 formed on the insulating member 18 and extending upwardly through circular apertures formed in the electrode 16. The upper electrode 17 has a central threaded aperture which is threadedly engaged by the terminal post 23 embedded in the insulating member 13 and extending upwardly beyond the projection 180. The lower end of the terminal post 23 extends into the cavity of the insulating member 18 within the flange 13b and is connected to a conductor 24 leading to the other terminal of the supply circuit.

In order to prevent contact of the fingers of the operator with the upper electrode 17, this electrode is provided with a cap or cover plate 25, formed preferably of porcelain or the like, which has a plurality of apertures 25a therein to permit the escape of steam which passes upwardly through corresponding apertures 17a which are formed in the upper electrode. The cover plate 25 is spaced from the upper electrode 17 by downwardly extending bosses 25:! which are secured to the electrode by metal tongues which are punched out of the metal plate of the electrode and turned upwardly to engage bosses 25d which project downwardly from the plate 25 and serve to space it from the upper ele trode so that a chamber is formed between the upper electrode and the body portion of the plate 25 to permit the free escape of steam and bubbles created by the passage of current through the water between the electrodes 16 and 17.

The construction of the heating unit 15 which has just been described permits the upper electrode 17 and the plate 25 to be removed readily for cleaning purposes and it also permits the insulating member 18 to be formed of high quality insulating material such as porcelain without the necessity of forming the entire body of the vessel it of the same material. Thus, the body portion of the vessel 11th may be formed of plastic material or the like which is relatively inexpensive, while the member 13 and the cap 25 may be formed of porcelain, having greater insulating qualities and better able to prevent arcing between the electrodes when there is no water in the vessel. In order to secure the insulating member 1% and the parts mounted thereon securely in place within the tubular extension 1(9 of the vessel, there is provided a metal retaining ring 26 which is internally threaded and which is adapted to surround the annular flange 1512 in threaded engagement with the projections 18 which are formed on the outer side of the flange 18b. When the retaining ring 26 is moved into threaded engagement with the projections 18), its lower curved flange 26a extends around the lower curved extremity of the flange 18b and its upper edge 26b seats against the lower surface of the flange 10g, independently of the use of cement or the like which may be employed for connecting the member 18 with the tubular xtension i i, and for providing a fluid-tight seal between them.

The bottles or other vessels to be sterilized are carried by a rack .36 which rests upon the bottom wall 1% and extends upwardly within the metal shell or cover 1.1. The rack 3ii'comprises an annular bottom ring 31 which rests upon the bottom wall of the vessel and which has opposite portions of its upper edges connected by transversely extending parallel rods 32. The ring 31 is connected by upwardly extending legs 33 with an annular ring 34 within which there is secured an annular series of small rings 35 which act as guides for bottles which are supported in inverted positions on the rods 32. The bottle supporting rings 35 are soldered or otherwise secured to the ring 34 and they are also secured to a central ring 36 by which they are held securely in assembled relationship.

The ring 36 is attached to two upwardly extending bars 37 which are provided at their lower ends with transversely extending supporting flanges 37a. These bars are provided at their upper ends with inwardly extending flanges 37b which are united by a U-shaped upwardly extending handle 37c. These flanges 37b serve as a support for a disk 38 which serves as a removable nipple support. This disk has an outer depending flange 38a, a central rectangular aperture 38b to receive the handle 37c and apertures 38:: to receive the necks of the nipples which are sterilized by the steam in the dome 11.

Although one form of the invention has been shown and described by way of illustration, it will be understood that it may be constructed in various other embodiments which come within the scope of the appended claims.

We claim:

1. A device of the class described, comprising a vessel formed of insulating material and adapted to contain a quantity of liquid to be vaporized, said vessel having a bottom wall provided with a relatively large single opening around which there is a downwardly extending tubular extension open at its lower end, said tubular extension having an inwardly extending annular flange formed. about its inner wall, an insulating member seated on the upper side of said flange and occupying the interior of said exten sion, a retaining ring having a threaded engagement with said insulating member below said flange and bearing against the underside of said flange to secure said insulating member on said flange in a liquid-tight manner, and spaced electrodes carried by said insulating member.

2. A device of the class described, comprising a vessel formed of insulating material and adapted to contain a quantity of liquid to be vaporized, said vessel having a bottom wall provided with a relatively large single opening around which there is a downwardly extending tubular extension open at its lower end, said tubular extension having an inwardly extending annular flange formed about its inner wall, an insulating member seated on the upper side of said flange and occupying the interior of said extension, a retaining ring having a threaded engagement with said insulating member below said flange and hearing against the underside of said flange to secure said insulating member on said flange in a liquid-tight manner, an electrode mounted on said insulating member, a second electrode detachably mounted above and spaced from said first named electrode, and an insulating cover plate mounted on said second electrode.

References Cited in the file of this patent UNITED STATES PATENTS 1,400,646 Webster Dec. 20, 1921 1,683,071 Hanks et al. Sept. 4, 1928 2,433,750 Fisher Dec. 30, 1947 2,555,229 Fisher May 29, 1951 2,582,781 Johnson Jan. 15, 1952 

